Biodiversity and the functioning of tropical forests

July 12, 2016
WDG

Biodiversity and the functioning of tropical forests
PhD defense University of Wageningen
Candidate: Masha T. van der Sande
Date: 06/07/2016

Watch Masha’s thesis defense on WUR TV (featuring W.D. Gosling as an opponent…)

WRUTVClick here to watch the video

Salamanca Villegas, S., van Soelen, E.E., Teunissen van Manen, M.L., Flantua, S.G.A., Santos, R.V., Roddaz, M., Dantas, E.L., van Loon, E., Sinninghe Damsté, J.S., Kim, J. & Hoorn, C. (2016) Amazon forest dynamics under changing abiotic conditions in the early Miocene (Colombian Amazonia). Journal of Biogeography online. DOI: 10.1111/jbi.12769

Lahr, M.M. et al. (2016) Inter-group violence among early Holocene hunter-gatherers of West Turkana, Kenya. Nature 529, 394-398. doi: 10.1038/nature16477

Rademaker, K., Hodgins, G., Moore, K., Zarrillo, S., Miller, C., Bromley, G.R.M., Leach, P., Reid, D.A., Yepez Alvarez, W. & Sandweiss, D.H. (2014) Paleoindian settlement of the high-altitude Peruvian Andes. Science 346, 466-469. doi: 10.1126/science.1258260

da Silva, S.G. & Tehrani, J.J. (2016) Comparative phylogenetic analyses uncover the ancient roots of Indo-European folktales. Royal Society Open Science 3. doi

Veenendaal, E.M. et al. (2015) Structural, physiognomic and above-ground biomass variation in savanna-forest transition zones on three continents – how different are co-occurring savanna and forest formations? Biogeosciences 12, 2927-2951. doi: 10.5194/bg-12-2927-2015

Netherlands Annual Ecology Meeting 2016 – day 2

February 10, 2016
WDG

NAEM_0Netherlands Annual Ecology Meeting (NAEM) 2016
10 February 2016
Conference Centre “De Werelt”, Lunteren

Day 2 of the NAEM breakfast 07:30, first lectures at 08:30… Two keynotes today thinking about ecological stoichiometry the first by Stan Harpole (Martin-Luther-Universitat-Halle-Wittenberg) focused on resource ratio theory, and then Martin Wassen (Utrecht University) thinking about N and P limitations. I also attended, parts of, three sessions today “Linkages between fire, vegetation, soil and ecosystem services”“Novel ecosystems”, and “Scaling from trait to environment and back”. My top talks for today were:

  1. Elmar Veenendaal (Wageningen University) Fire effects on tropical woody vegetation structure have been exaggerated?
    Working on long-term fire study plots (Kokondekro since 1932) suggest that for forest-savannah transition zones fire alone is insufficient to mediate a change between states; human manipulation of ecosystems is required as well to trigger the change.
  2. Frank van Langevelde (Wageningen University) Feedbacks between fire and patches of woody vegetation in tropical grassland savannah
    Examination of tree distributions and fire within the Kruger National Park shows that landscapes contain more clustered tree populations when fire frequency is higher.

Plus today I have done lots of talking and made many new contacts. I have lots of follow up emails to write and promised papers to send around! Overall this has been a super meeting for meeting people – perfect for expanding my network of Dutch based ecologists – in a nice location, with good food and beer. Looking forward to next year already.

Netherlands Annual Ecology Meeting 2016 – day 1

February 10, 2016
WDG

NAEM_0Netherlands Annual Ecology Meeting (NAEM) 2016
9 February 2016
Conference Centre “De Werelt”, Lunteren

The annual Dutch ecology conference is being held over two days at the in “remote” Lunteren and I am pleased to be able to attend all of the conference this year. The conference was kicked off this morning with a recognition that this year is 150 years since the birth of ecology as a science (Haeckel, 1866). The opening two keynotes focused on aspects of ecology which have sometimes been overlooked firstly, parasitism (Peter Hudson, Penn State University) and secondly, immunology (Irene Tieleman, University of Groningen). Following these I focused on just two sessions in the morning “linking diversity to function”, and in the afternoon “ecosystem cascades”. From the range of excellent talks in the sessions I have picked one from each as my favourite:

  1. Masha van der Sande (Wageningen University) The role of biodiversity and environment on productivity in tropical forests; evidence across scales
    By examining long-term tropical forest monitoring data van der Sande demonstrated that through time ecosystem traits changed significantly. She hypothesised that the lack of stability in ecosystem traits was due to past disturbance; although it is unclear what caused this disturbance (climate or humans), or when it occurred.
  2. Dries Kuijper (Mammal Research Institute, Poland) Landscapes of fear in Europe: Wolves and humans shaping ungulate top-down effects
    By tracking Wolf pack distributions in the Bialowieza forest (Poland) Kuijper showed that ungulates avoided Wolf pack  “core areas” for fear of predation, that the exclusion of ungulates lead to reduced browsing of the vegetation, and so consequently forests regenerated faster in Wolf pack core areas.

The evening lecture was given by Bart Knols (in2care) who gave an impassioned talk on the importance of communicating science beyond the academic sphere. Arguing that now is the time for ecologists to have an influence on policy making, politics and business, as well as showing us how he has done this.

Great day.

Continue Reading

Keen PhD Thesis 2015

September 30, 2015
WDG

Hayley Keen getting excited about sediments during fieldwork in Ecuador (2012). Photo: J. Malley

Hayley Keen getting excited about sediments during fieldwork in Ecuador (2012). Photo: J. Malley

Keen, H.F. (2015) Past environmental change on the eastern Andean flank, Ecuador. PhD Thesis, Department of Environment, Earth & Ecosystems, The Open University.

Abstract
The eastern Andean flank of Ecuador (EAF) contains some of the world’s most biodiverse ecosystems. Andean montane forests are threatened due to anthropogenic pressures and both current and projected climate change. This thesis examines the palaeoecological history of two stratigraphic sequences (Mera Tigre West [MTW] and Mera Tigre East [MTE]) obtained from the Ecuadorian modern lower montane forest. The sediments preserved were analysed using eight analytical techniques, allowing an insight into the ecosystem’s potential response to projected changes derived from their past responses. Palaeoecological studies on the EAF are rare, and those that do exist are debated relating to: i) the inference of robust ecological data from pollen records in floristically diverse locations, and ii) the past source area of sediments preserved in fluvially exposed sequences, potentially leading to contamination with older material.

A statistical sub-sampling tool was developed (debate i), capable of producing statistically robust count sizes for each pollen sample; MTW and MTE count sizes ranged from 196-982 showing the diversity within sequences. The depositional environment of MTE was analysed, investigating sediment provenance throughout (debate ii). Results found that large scale volcanic events were critical in the preservation of the sediments, whereas fluvial influence caused a regional sediment source area in the upper stratigraphy, impacting on the palynological interpretation of MTE. Pollen records demonstrated the presence of a diverse vegetation community with no modern analogue at MTE (abundant taxa (>15 %): Hedyosmum, Wettinia, Ilex) and upper montane forest at MTW (Alnus, Hedyosmum, Podocarpus). Fire was not the main driver for the vegetation reassortment at either site (MTW correlation coefficient: -0.37, MTE: 0.16). The two sites have demonstrated the EAF plays host to floristically dynamic ecosystems, susceptible to drivers of change (fire and landscape) and should be considered when predicting the montane forests’ future response to environmental change.

Supervisors: Dr. William D. Gosling (The Open University/University of Amsterdam), Dr. Encarni Montoya and Dr. Sarah Sherlock (both The Open University).
Examiners: Dr. Dunia Urrego (University of Exeter), and Prof. David Gowing (The Open University).
Chair: Dr. Mark Brandon (The Open University).

To borrow a copy from The Open University Library click here.

Publications (so far): Continue Reading

Past environmental change in the Amazon basin – AGU video

September 8, 2014
WDG

Hayley Keen’s video “Past environmental change in the Amazon basin” has been shortlisted for the American Geophysical Union (AGU) student video prize. Please watch and like Hayley’s video; top “Liked” videos will win entry to the AGU 2014 Fall meeting.

View all the videos on the AGU YouTube channel.

News articles:

Unesco to rule on Tasmania forest and Great Barrier Reef, BBC News Asia.

Climate change will ‘cost world far more than estimated’, by Tom Bawden, The Independent.

Scientific articles:

Heslop-Harrison, J. (1979) Aspects of the structure, cytochemistry and germination of the pollen of Rye (Secale cereale L.). Annals of Botany, 44, 1-47.
Summary (Adele): Sometimes, the old ones are the best, and this behemoth of a paper contains a huge amount of useful information on the chemical structure and development of Rye pollen grains. As I am working on the chemistry of grass pollen at the moment, it is incredibly useful to know that this sort of information exists and can be used to inform both my experimental protocol and interpretations.

Michelutti, N., Blais, J.M., Cumming, B.F., Paterson, A.M., Rühland, K., Wolfe, A.P. & Smol, J.P. (2010) Do spectrally inferred determinations of chlorophyll a reflect trends in lake trophic status? Journal of Paleolimnology, 43, 205-217. doi: 10.1007/s10933-009-9325-8
Summary (Frazer): Quick and easy way to extract data from lake sediment cores.

Rossetti, D.F., de Toledo, P.M and Góes, A.M. (2005) New geological framework for Western Amazonia (Brazil) and implications for biogeography and evolution. Quaternary Research, 63, 78 – 89. doi: 10.1016/j.ygres.2004.10.001.
Summary (Hayley): Research discussing the importance of understanding the underlying geological processes in order to correctly identify the mechanisms controlling modern biodiversity in Western Amazonia, Brazil.

Simpson, J. (2011) On the Ambiguity of Elves. Folklore, 122, 76-83. DOI: 10.1080/0015587X.2011.537133
Summary (Will): Elves depicted in modern literature have a grounding in ancient literature.

Trenkamp, R., Kellogg, J. N., Freymueller, J.T. and Mora, H.P. (2002) Wide plate margin deformation, southern Central America and northwestern South America, CASA GPS observations. Journal of South American Earth Sciences. 15, 157 – 171. PIL: S0895-9811(02)00018-4.
Summary (Hayley): GPS data used to detect plate boundary convergence, subduction and collision within the north west of South America. GPS data between 1991 and 1998 was used to work out rates of movement for plates.

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